Fluid ready to use, economical and ecological. SLICK RTU is a completely synthetic, transparent and solvent-free soldering agent. The product is Silicon free. Applied to areas adjacent to the areas to be welded, it prevents slag and fusion sprays from adhering, facilitating subsequent cleaning steps. SLICK RTU is used in all continuous wire welding, laser cutting and metalworking processes where there are incandescent waste emissions. The particular totally synthetic base and the absence of solvents, allows the use of SLICK RTU even in cases where there is a high formation of slag, in contact with which SLICK RTU does not develop harmful and polluting gases, safeguarding health operator and environment. METHOD OF USE SLICK RTU is used as it is using normal sprays. SLICK RTU is sprayed in the welding torch and on the surfaces involved in laser cutting.